Lubricating oil



Petenicd June 19, 1945 UNITED STATES PATENT OFFICE No Drawing.Application February 14, 1942, Serial No. 430,897

Claims.

This invention relates to modified lubricating oils and especially tothose which have been modified by the addition of constituentsparticularly adapting the oils to severe service uses as in Dieselengines, high out-put aviation engines and the like.

It is well understood that various lubricating oils as ordinarilyrefined are inadequate to meet many uses, particularly severe serviceuses, because of the development of resinous and varnish-like materialswhich cause ring sticking and similar diiiiculties. It is also wellunderstood that, where highly corrosion sensitive bearings are used suchas cadmium-silver and copper-lead bearings, the ordinary lubricatingoils develop conditions during use which are corrosive to said bearings.In many instances where additives have been used to overcome ringsticking dimculties, these additives have promoted the development ofcorrosive conditions.

An important object of this invention is to produce a compounded oilwherein the additives overcome the formation ofsaid resinous materialsor prevent their deposition and at the same time avoid the developmentof the mentioned corrosive conditions.

According to this invention, two constituents ordinarily are employed,one of which is a detergent material having the properties of preventingthe accumulation of said resinous or varnish-like deposits, and theother of which acts to overcome or prevent the development of corrosiveconditions in the oil during use and may be termed an anti-corrosion"agent. This latter additivemay act as an anti-oxidant or it may act as areserve alkalinity agent serving to neutralize synthetic acids producedin the oil during use. Both materials should be free from any impuritiesor other constituents which possess catalytic activity toward theproduction of corrosive conditions and the like.

According to a preferred form of the present invention, the detergentmaterial is an oil-soluble metal soap of the sulfonates produced frompetroleum, which sulfonates are to be free from salts exerting thementioned catalytic activity. For example, calcium sulfonates obtainedfrom sulfonic acids produced by strong sulfuric acid treatment ofpetroleum lubricating oils are used, these being so produced as to befree from iron sulfonates or other metal salts having said catalyticcharacteristics. In general the alkaline earth metal salts are found tobe free from such catalytic properties. The other type of additive,which is referred to as an "anti-corrosion agent,"

preferably will be of the class which possess "reserve alkalinity"properties and may also contain a constituent having some inhibitingvalue. An example is an oil-soluble salt, such as the calcium salt, of adialkyl-substituted' phenol thioether. Such an alkylated phenolthioether, or alkylated diphenol sulfide, is obtainable on the marketunder the trade name Paranox and is produced by the Standard OilDevelopment Company. Another anti-corrosion agent that may besatisfactorily used with the pure oil-soluble sulfonate is a zinc saltof the reaction product of methyl cyclohexanol with phosphoruspentasulfide. Another suitable anti-corrosion agent is the calcium saltof phosphonic acids produced by heating a mineral lubricating oil orsimilar petroleum fraction with phosphorus and blowing the reactionproduct with air to produce a phosphonic acid. Also, oil-soluble metalsalts or reaction products oi Pass with other aliphatic alcohols may beused.

Another feature of the invention resides in the use of oil-solublesulfonates as detergents which are free from the mentioned objectionablesalts and are in the form of both the green" acid sulfonates andmahogany acid sulfonates produced in situ in the sulfonated oil andwithout separation of the sulfonates from the oil and without separationof the water-soluble green acid sulfonates from the oil-soluble mahoganyacid sulfonates. The invention also resides in the method of producingthese mixed sulfonates, and in the production or oil containing them.The invention resides not only in the use of these sulfonates asdetergents with other described types of materials in an oil but intheir use as the sole constituent in an oil or with: any other type ofconstituent not here specified.

In practising the invention, it is applicable to both parafiinic typeoils and naphthenic type oils. Inasmuch as it has become desirable toemploy oils of high viscosity index (V. I.) in the preparation oi Dieselengine oils and other severe service oils, the adaptability of thepresent additives to high V. 1. oils is another advantage of the presentinvention.

As the terms are used herein, "oil-soluble reters to a high state ofcolloidal dispersion of the soaps or'salts in question such that theymaintain themselves permanently dispersed in the oil so as to approach astate of true solution. The term "reserve alkalinity," as has beenindicated, refers to the property of the additive to neutralizesynthetic acidity developed in the lubricating oil dtu'ing use. The term"anti-corrosion refers to the properties of the materials to neutralizesuch synthetic acidity or to inhibit oxidation which otherwise wouldresult in corroslve conditions. The term "detergent" refers to theproperty of the additive either to remove deposits of resinous andkindred materials, or to prevent their formation or deposit. The termviscosity index" (V. I.) indicates the type of oil. A parailin base oilis assigned the V. I. of 100 and certain Gulf Coast naphthene base oilsare issigned the V. I. of zero. Thus, high V. I. oils are the so-calledhighly parafllnic oils, such as Pennsylvania oils and those highlyrefined with selective solvents. The term is defined in Chemical andMetallurgical Engineering, vol. 36 (1929) pages 618 and 619. A kindredterm is "viscosity-gravity-constant (V. G. C.) where lower valuesindicate greater "paraflnicityk see Journal of Industrial andEngineering Chemistry, vol. (1928) page 641. The term "soap" indicatesthose metal salts of high molecular weight acidic materials possessingat least ten carbon atoms per molecule to impart good disersibility orsolubility in mineral lubricating oil. The term sulfonates refers tothose salts or soaps produced from the well-known sulfonic acidsobtained by sulionation of petroleum fractions, especially certainlubricating fractions herein described. as by means of concentrated orfuming sulfuric acid, or chlorosulfonic acid, or suliur dioxide, or thelike, familiar to the skilled chemist.

In preparing the oil-soluble additive salts of this invention, variousmetals may be used so long as the salts themselves, or other salts whichmay form in use, do not catalyze or otherwise produce corrosiveconditions. In general, the alkaline earth metal salts may be usedthroughout. Also zinc and apparently aluminum salts may be used.Apparently all these metals and most other metals may be used for thephosphorus-bearing salts described if the salts are oil-soluble.

The various additive materials employed according to this invention maybe produced in manners herein described. In employing these variousmaterials, small amounts are dispersed in a mineral lubricating oil inproportions to yield the desired eflects without however materiallyincreasing the viscosity of the oil and without imparting grease-likecharacteristics. Quite commonly about 1% of each of the two types ofindicated additives is employed. Ordinarily between about 1% and 1.5% o!the sulfonate is used, e. g. 1.2%, and from about 0.5% to about 1% ofthe anti-corrosion additive is used, e. g. 0.7% of the calcium salt ofthe indicated alkylsubstituted diphenol sulfide. In preparing thevarious oil-soluble additive materials, they may be obtained asconcentrates in a lubricating oil similar to or identical with ordifferent from the lubricating oil to which they are finally added.Production of the final product is readily obtained simply by dilutionand by thorough mixing. Otherwise the various soaps or salts are readilydispersed in lubricating oil by sufllcient agitation, accomplished ifdesired with a limited amount of heating, such as to 150 C. orthereabouts.

Where concentrates are prepared they will normally contain from about10% to 40% or 50% of the additive, according to the method ofpreparation.

In the final product the over-all ranges for each of the two additiveswould normally be from aroimd. 0.4% or 0.5% to perhaps 1.5% or 2%.Commonly the total of all additives will not exceed about 2%. As toindividual additives probably not more than 3% would ever be. employed,both for the reason that viscosity increase is apt to be too great andfor the "further reason that larger amounts do not appear to offer anyparticular advantage and merely serve to increase the cost. For lowerlimits it is probable that any appreciable percentage would afford someadvantage. The indicated intermediate range in the order of 1% appearsto be commercially preferable.

Sullonates In preparing the sulfonates which constitute one of the twoprincipal additives of this invention, it is important first to select alubricating oil fraction which will provide a substantial yield of thedesired sulfonate. For this purpose certain lubricating oils of bothnaphthenic and parafllnic type have been found acceptable, and thisapparently is true regardless of their viscosity. In general,lubricating oils which have been prepared by a moderate degree ofrefinement are best. This distinguishes them from those lubricating oilswhich have been heavily refined as by the more modern severe solventtreatment, and from the lightly acid treated lubricating oils well knownespecially several years ago. To illustrate, a lightly acid refinednaphthenic type oil, e. g. Western base oil treated with 20 to 30 poundsof 98% sulfuric acid per barrel, is not desirable for the presentpurpose; practically all of the acid used in subsequently sulfonatingthe oil is consumed in producing sludge, and the percentage ofacceptable sulfonate is negligible. Similarly, where a highly solventtreated more modern type of lubricating oil, e. g. one of very highviscosity index produced by severe solvent extraction with benzol-sulfurdioxide mixtures, or furfural, or dichlorethyl ether or the like, isused, sulfonatable materials of the required type apparently have beenlargely removed and the result of attempting to sulfonate is theformation only of a small quantity or objectionable sludge.

On the other hand a naphthenic base oil which has been subjected to alight sulfuric acid treatment (e, g. 20 pounds of 98% acid per .barrel)and also to a moderate treatment with liquid sulfur dioxide so as toyield a lubricating oil of about 25 V. L, is a good stock. Similarly amixed base oil moderately treated as by selective solvent extraction toyield a V. I. of about is a good stock. Again, a Pennsylvania oilmoderately treated to a V. I. of 104 and having a viscosity gravityconstant of 0.812, is a good stock. But a medicinal white oil having aV. I. of 72 and a viscosity gravity constant of 0.826 yieldssubstantially no acceptacle sulfonates. Thus neither viscosity index norviscosity gravity constant, nor in fact the type of oil, appears todetermine a good stock. On the other hand it appears to be the degree ofrefinement, which has here been designated as an intermediaterefinement. Of course it is true that, with the possible exception ofwhite oils, a small amount of sulfonate may be obtained from almost anylubricating oil, but unless the oils come within the above designationof intermediate refinement they are not commercially acceptable. Oils ofS. A. E. 40 grade have been commonly used but lighter stock such as S.A. E. 20 and heavier stock such as S. A. E. 60 also have been employed.

Specific oils which have been made are given of about 125 F. to about175 F. In practice about 150 F. to 160 F. is maintained for the reasonthat much higher temperatures tend to below, the first six, indicated as"good or better. being acceptable, whereas the last five, indicated asbad" or worse, are of little or no practical value. decompose some ofthe sulfonic acids. The pres- Bulionam 011 type Treatment V. I V. G. 0.Gunmen Naphtllenic:

S. A. E. 40 25$ H,SO4/bbl. followed by S0, 25 0.862 Highest. 8. A. E.Same as for S. A. E. 40 0.862 Do. Paraillnic: S. A. E. 40. Very moderateselective solvent... 82 0. 815 High. Pennsylvania: S. A. E. 40 Usual (noselective s lvent) 104 0. 812 Do. Paraflinic:

s A, Moderate selective solvent... 90 0.804 Good.

Same as for S. A. E. 40 90 0.81 Do. Heavy selective solvent.... 100 0.80Bad.

Normal 130 0. 77 Do. 25#H1S04/bb1. -20 Very bad. No trash.-- 20 0.88 Do.

Heavy 72 0. 826 Zero.

In sulfonating a suitable lubricating 011 fracence of the added watermakes it easier to keep tion, the desired quantity is heated to about135 F. in a vessel which, under the conditions of treatment, will notyield in the product objectionable metal salts, e, g. iron salts. Forexample glass or silica vessels may be employed or steel alloys or thelike not subject to attack in treating with the strong acids used.Higher and lower temperatures may be employed, such as down perhaps toas low as 50 F., or perhaps as high as 175 F., but most satisfactoryresults havebeen obtained where operating at 135 F. Similarly by weightof a 40% fuming sulfuric acid has been found to be especially suitablefor the present purposes, and as little as 20% or 30% fuming acid hasbeen used with satisfactory results. According to a preferred procedure,having heated the oil to 135 F., the acid is gradually added at a rateslow enough to keep the temperature at about 135 F. If necessary tocontrol the temperature, cooling will be employed and this may be aredown the temperature, and it also tends to facilitate theneutralization operation. By reason of the presence of the water thetemperature of course can always be kept at least below the boilingpoint of the water.

Having completed the addition of the 30% of the lime, which is inexcess, all excess sulfuric acid will have been neutralized with theformation of solid calcium sulfate, and the sulfonic acids will havebeen converted into calcium sulfonates.

It will be noted that according to this method of procedure, the acidsludge containing the socalled green acids has not been removed from theoil solution of the oil-soluble so-called mahogany" acids. As a result,when the whole batch is neutralized with lime, both the oil-solublemahogany acids' and the oil-insoluble green acids are converted intocalcium sulfonates. The mahogany acid soaps are inherently soluble inquirement where working large batches. In 40 the oil and at the sametime they act as solubillztreating small amounts the time of additionmay ers for the green acid soaps. Inasmuch as the be as little asfifteen minutes, whereas in hangreen acid soaps are substantially asvaluable dling large batches two or three hours or even for detergentsas are the mahogany acid soaps, longer may be required for addition ofthe fumthis method of procedure avoids the cumbersome ing acid. Duringthe addition the mass is agitatand expensive separation of the two typesof ed continuously to insure complete contact and acids. At the sametime it increases the suldispersion. Upon completion of the addition offonate content of any given batch. the acid, sulfonation of the oilappears to be com- Having completed the neutralization operation plete.In addition to the indicated fuming acids, whereby an oil solution isobtained of both the other sufiiciently effective acid strengths may begreen acid soaps and the mahogany acid soaps, used. Thus, acids from 98%H2804 up to pure the next step is to evaporate the water. This is SO:may be used, i. e. from concentrated H2804 accomplished by heating thebatch at about 325 to 100% fuming acid, Possibly as low as 92% or F. (orwithin a range of about 275 F. to 375 F.) even 90% H2804 may be employedin some inuntil the water is expelled. stances. The next step is toremove the solids and leave After completion of the acid addition, it isdea product in the form of a soap-oil concentrate. sirable according tothe preferred form of this Conveniently the dehydrated batch is dilutedinvention to add a quantity of water to facilitate with about one-halfagain as much oil, or naphthe subsequent neutralization operation. Thethe if preferred, and well mixed. No more addiaddition of 10% of wateris beneficial, and more tional oil or naphtha should be employed thanmay be conveniently added up to the optimum sumcient to make thebatchadequately fluid for of about 30%, or even up to 100% based on thesubsequent separation of solids. Solid separa- 011 tion is bestaccomplished by settling the batch About 30% of water is adequate forthe refor about twenty-four hours at about 200 F., quired purpose andthe addition of more results and then filtering or preferablycentrifuging the chiefly in the objectionable necessity of subsebatch.Where initial settling iseffected, the subquently boiling it 011.sequent filtering or centrifuging leaves a clear Following the additionof water, the next step pr ct consisting of n ulf nate oil on ainin isto neutralize the sulfonated oil batch. This is abo 0% 0f calciumsulfonate. This is an Oil accomplished by slowly stirring in a limeslurry concentrate which may be added in appropriate consisting of aboutequal parts of water and lime, quantities to any desired lubricatin ilin l n the lime approximating about 30% of the suling & final Pr ionatedoil. The lime slurry is added at a rate If. for any reason It be deemedd ira to such as to keep the temperature within the limits eliminate thegreen acid soaps from the product,

the acid sludge will have been separated from the batch followingsuli'onation and before neutralization.

If it should be that, in the sulionation and soap making procedures,objectionable metal salts have been produced, such as iron salts, theoilsoap batch may be treated in any appropriate manner for theseparation of the iron. For example materials which will react with theiron soap to form oil-insoluble compounds or inactive iron complexes maybe added, such as cupferron, ammonium thiocyanate, acetylacetone, 8-hydroxyquinoline, diphenylamine, phenanthroline, and the like familiarto the organic chemist. Or, a finely divided active metal above iron inthe electromotive series may be added, such as calcium, magnesium,aluminum or zinc, in which case metallic iron is formed, and theresultant soaps are not active oxidation catalysts. When using any ofthe above agents to bring down oilinsoluble forms of iron, this may takeplace before removing the excess lime and calcium sulfate, so that allinsolubles may be removed in one settling, filtering or centrifugingoperation.

The sulfonates are also made by recovering the sulfonic acids from thesulfonated oils as sodium sulfonates by sodium hydroxide treatment inthe well known manner, and then converting by metathesis, as with CaCl:or Ca(NO3)2, to calcium or other desired salts. But, where necessary toeliminate objectionable impurities, the sulfonic acids are "cracked out"from the sodium sulfonates with sulfuric acid of about 50% or greaterconcentration (thereby avoiding any tendency for either green acids ormahogany" acids to dissolve in weaker sulfuric acid solutions). Theobjectionable materials pass into the lower aqueous layer, and the toplayer is the liberated suifonic acids from which desired calcium orother soaps are produced, as with lime or calcium hydroxide or othersuitable base. However, inasmuch as the sulfonates are eventuallyrequired in oil, round-about and expensive procedures are avoided merelyby the production of the calcium sulfonates or other appropriateoil-soluble metal sulfonates in situ in the oil used for the sulfonationoperation. Thereafter, simple dilution with more oil of appropriategrade is all that is required for the lubricating oil product desired.

Phenol-thio-ether soaps With respect to the second additive requiredaccording to this invention for the purpose of introducing ananti-corrosion agent, ordinarily I prefer to employ calcium soap of thephenolic thio-ether above indicated as Paranox. The Paranox type ofmaterial carries an alkyl substituent in each ring, such as butyl ortertiary amyl. One particular material is para-tertiary-amyl phenolsulfide, where one or more sulfurs appear in the ether position. Againinstead of being a simple thio-ether containing two rings, it isprobable that the commercial material contains several additional ringslinked together with sulfur, Thus the structural formula for thepara-tertiary-amyl phenol sulfide (thio-ether) with only two rings maybe represented as follows:

8 CH CHs The above probably is extended by the addition or furtheralkylated phenol groups connected with additional sulfur atoms, thus:

R(CsHaOH)S(CeHzOH)R.8(CsHaOH)R.S

where R represents the alkyl substituent. Materials of this type havebeen described in the Mikeska Patents Nos. 2,139,766 and 2,139,321.

Suitable metal salts, such as calcium salts of the above phenolicsulfides may be prepared in any manner desired by the skilled chemist.One satisfactory method has been to add the starting material to anappropriate equal quantity, or even greater quantity of a suitablelubricating oil having good solvent properties for the phenolic materialand for the salts to be produced. Good naphthenic base mineral oil ofintermediate degree of refinement is a good example. This mixture of oiland phenol sulfide is commingled with an excess of hydrated calciumoxide and a small proportion of water, and the mass heated to about 300F. under agitation for a sumcient time to insure neutralization andsatisfactory subsequent dehydration. The resultant batch is thenfiltered or centrifuged to remove solids such as the excess calciumoxide. The ash content has been increased by partially neutralizing at atemperature around 200 F. to 210 F., then cooling to around F. to F.,then adding around 3% of 95% alcohol, and then raising the temperatureof the mass to said 300 F. to complete the neutralization.

According to another method the alkyl phenol sulfide has beenneutralized with sodium hydroxide and then converted by metathesis withcalcium chloride or the like to yield the calcium salt required.Commonly the starting material is a concentrate containing about 20% ofphenol sulfides and 80% of a lubricating oil. If this is not too viscousfor convenient handling further amounts of lubricating oil need not beadded, unless the soap-dissolving powder of the oil is not entirelyadequate.

The above described neutralization is easily accomplished due to thefact that the phenolic material itself has an acid number in theneighborhood of 98. The resultant salts may be generally represented asfollows:

In compounding a lubricating oil of the present invention for practicaluses, sufllcient of the concentrate of the phenolic materials described,such as the mentioned calcium Paranox" soap. and of the sulfonateconcentrate, are added to impart a soap content of each or thesematerials in the order of from perhaps 0.5% to 3%. In actual practicethere is commonly employed about 1% Or a little less (e. g. 0.7%) of thephenolic soap, and about 1% or a little more (e. g. 1.2%) of thesulfonate.

Thio phosphates As substitutes for the phenol thio-ether salts to beused as a second additive along with sulfonate, certain types of thiophosphates may be used. phosphates will be added to the finallubricating product. Any suitable oil-soluble metal salt is employedsuch as a zinc salt or a calcium salt. These phosphates are obtained byreacting phosphorus pentasulfide with aliphatic alcohols. Primarilythese products will be referred to by their method of preparationbecause of the fact that their composition is not certain and for thefurther reason that the product probably consists of a mixture ofcompounds. One important alcohol employed is methyl-cyclo-hexanol andanother is octyl alcohol or ethyl-hexyl-alcohol.

In some instances, where these phosphates are employed, it may bedesirable to use them as a third constituent where the phenol sulfidesalts are employed along with the sulfonate s.

The oil-soluble metal salts of these reaction products may be preparedby reacting the phosphorus pentasulfide with the alcohol to prepare anintermediate acidic reaction product, and then treating such productwith a metal oxide or the like to produce a metal salt thereof; or anyappropriate single step operation may be used.

With respect to the reaction between the phosphorus pentasulfide and thealkylated cyclo-aliphatic alcohols mentioned, cyclo-hexanol alkylatedwith aliphatic chains containing less than ten carbon atoms andpreferably about five or less, such as methyl, ethyl, propyl and amylcyclo-hexanols are preferred. In fact, cyclohexanol or cyclo-heptanol orcyclo-pentanol may be used, and also methyl cyclo-heptanol and methylcyclo-pentanol, and the like, so long as the respective salts desiredare oil-soluble. Or a mixture of these cyclo-aliphatic alcohols could beemployed. While oil-soluble salts of other metals are acceptable, thezinc salt has so far been found preferable, and the methods ofpreparation given will refer particularly to the zinc salt.Nevertheless, those oil-soluble metal salts producible from other metalshereinbefore mentioned as bein appropriate for the preparation of thesulfonates and the phenolic thio-ether soaps, may be used. For example,the lead salts of the reaction product of phosphorus pentasulflde withoctyl alcohol have been found acceptable, as well as the zinc salts.

Thiophosphate of alkyl cyclo-heranoL-Five mols of methyl cyclo-hexanolare reacted with one mol of PzsSs. For example, five hundred grams ofmethyl cyclo-hexanol were mixed in an equal volume of benzene with onehundred ninety-five grams of phosphorus pentasulfide in a flask. Thismixture was heated in a water bath at around 212 F. and refluxed forfour hours. The batch was then cooled to about 140 F. and washed with anequal volume of water at about l40 F; The benzene was then removed fromthe washed material by distillation at atmospheric pressure.

The resultant reaction product is believed to be a mixture of acidthiophosphate esters such as represented by the following formulae whereR is the cycle-aliphatic radical derived from the' alcohol, and R ishydrogen or R:

SH on on S=POR' O=PSR O==POH \OR SR' sR In general around 4% to 1% ofthese- Other possible materials are represented by the following:

Employing the mixed reaction product from the above described operation,this acid ester was mixed with water to make about a 20% mixture whichwas neutralized with aqueous caustic soda solution at about F. To thissolution was added an aqueous solution of zinc chloride with agitation,whereupon the zinc salt formed and settled out. The water was poured offand the zinc salt dehydrated by dissolving the wet zinc salt in abouttwice its volume of benzene, the water and benzene then being removed byvacuum distillation under maximum temperature conditions of 212 F. withseven inches vacuum.

In another instance the methyl cyclo-hexanol and zinc oxide were heatedin a container to about 180 F. Phosphorus pentasulfide in finely dividedform was then introduced over a period of about forty minutes at atemperature not exceeding 212 F., the temperature then being raised to320 F. over a period of an hour maintained for an additional half hour.The product is recovered by dissolving in an approximately equal weightof mineral oil and filtering hot, employing preferably a filter aid, e.g. 2% of Filtrol; or the product may be dissolved in benzol, filteredand the benzol removed by vacuum distillation.

Thiophosphate of octyl alcohol-One gram mol of powdered phosphoruspentasulfide is added to four gram mols of octyl alcohol in a glass orceramic container, and the mixture agitated at temperatures between 250F. and 300 F. for about two hours, i. e. until the phosphoruspentasulfide dissolves. When 250 F. is reached, the reaction is rapidwith evolution of hydrogen-sulfide. This liquid product is then treatedat similar temperatures, e. g. 250 F., with an excess of either powderedmetal or powdered metallic oxide, for example, powdered zinc or zincoxide, until no more dissolves, as by standing over night at 250 F.Usually it is deemed preferable to use the metallic oxide. The resultantmetal octyl thiophosphate, for example, the zinc salt, is readily takenup in mineral oil solution, employing either parafiinic or naphthenictype 011. The mere introduction of the salt into the oil with mildagitation and limited heating is sufficient to produce an oil solutionto yield a concentrate, which in turn readily disperses in the final oilproduct to which it is added.

One particular material made in this manner analyzed 18.1% sulfur and9.3% phosphorus, indicating the di-octyl thiophosphate as the principalconstituent of the product with the probable formula:

SH S=POC3H11 OCsHu Apparently the mono-octyl thiophosphate also ispresent with the probable formula:

Quite likely other thiophosphate esters of the types above indicated inconnection with the cyclohexanol product are also present ingreater orlesser proportions.

In addition to the zinc octyl thiophosphate described, the lead, copper,manganese, iron and tin salts also have been prepared by employingoxides thereof and allowing the mixtures to stand over night at about250 F. as above. Upon decanting and filtering, viscous liquids wereobtained. Other appropriate salts are the alkaline earth metal salts,such as the calcium salt, and salts of other metals as indicated inconnection with the sulfonates and phenolic thio-ether salts.

As a substitute for octyl alcohol other alcohols which yield oil-solublesalts and contain fewer than ten carbon atoms are preferred, althoughalcohols containing ten or more carbon atoms may be used at least forsome purposes. For example, butyl, amyl, iso-amyl, hexyl and heptylalcohols may be employed. As to the heavier alcohols, lauryl, cetyl andthe like may be employed, and these may sometimes be modified byinclusion of phenyl or kindred aromatic groups and the like,particularly as oil-solubility and stability may be improved.

The various salts produced from the corresponding esters are probablymixtures of such types as the following, where R is the organic radicalof th alcohol used and Zn represents any appropriate metal as well aszinc:

These various metal salts of the thiophosphate esters described, thatis, the reaction products of phosphorus pentasuli'ide with the indicatedalcohols, are readily oil-soluble for the purpose of producingconcentrates or final blends, and are employed in conjunction with thementioned sulfonates and phenolic thio-ether salts ordinarily in theproportion of about 0.5% of the thiophosphate ester salt based on thetotal composition, or between about 0.1% and 1.5%.

Phosphorus acid salts tained from phosphorizing mineral lubricating oilfractions of so-called highly-paraflinic character or of high viscosityindex. According to the best modern authorities on the constitution ofmineral lubricating oil of this type, the molecules are not entirelyaliphatic or chain compounds but are mixed or complex moleculescontaining aromatic or naphthenic rings protected by aliphatic orparaiiinic side chains which may in themselves be straight chains orbranched chains. Or such oils may be mixtures of molecules whereinaromatic or benzene rings are protected by aliphatic chains, and whereinnaphthene rings are protected by aliphatic chains. Naphthenic typelubricating oils may be used, and also other hydrocarbons such asparaiiin wax and the like as above mentioned. On phosphorizing thesematerials the phosphorus grouping apparently enters more readily toreplace a hydrogen atom connected to one of the carbons of the aliphaticchain. This phosphorus grouping apparently may be connected either to anend carbon of the chain portion of the molecule or to an intermediatecarbon of said chain portion, and the phosphorus grouping of theresultant phosphonic acids apparently has the arrangement:

O Ill-P 011 However, while there seems to be ample evidence that this isthe structure, I nevertheless do not wish to be bound in all events bythis theory. It is possible also that a portion of the total phosphorusmay be attached to naphthenic rings, or to aromatic rings, when such arepresent.

Other hydrocarbons such as wax, gasoline, kerosene, gas oil, solventextract from lubricating oil, coal tar distillate fractions, andhydrocarbon derivatives such as chlorinated or oxidized or otherwisemodified hydrocarbons also may be similarly phosphorized with theproduction of similar useful compounds. Halogenation or oxidation mayfacilitate phosphonation or subsequent reactions. If oxidized startingmaterials are employed and they contain carboxylic acids. phosphonationshould be complete enough to reduce all the acids before air-blowing, orthe carboxylic acids may be removed before phosphonation as by selectivesolvent extraction, because the acids represent the objectionable typeof material which it is sought to avoid in the present product.

In phosphorizing mineral lubricating oils, preparatory to oxidizing thephosphorized materials to yield the phosphonic acids, I have employeddifferent procedures. According to one procedure the oil itself isheated to incipient cracking" or decomposition and yellow phosphoruslumps are added with heating at appropriate temperatures such as up toabout 600 F. until the phosphorizing reaction is complete. (Yellowphosphorus is the commercial term for white phosphorus which ordinarilycontains small quantities of red phosphorus sufllcient to give it ayellow color.) In thi instance, a nitrogen, carbon dioxide or otherinert atmosphere may be employed for safety purposes. According toanother operation the mineral oil is first chlorinated to facilitatesubsequent phosphorinatlon. This may be done by bubbling a chlorine gastherethrough until the weight is increased by chlorine addition to anextent or perhaps but preferably less, e. g. 2%. This material after asuitable washing is then phosphorized by heating for appropriate periodsto incipient cracking"-or decomposition with addition of yellowphosphorus lumps until suitable phosphorination is produced. In thiscase lower temperatures such as a maximum of about 475 F. will suffice.

Oxidation-Following phosphorization for an appropriate time, for exampleone to three hours, the charge is cooled to about 200 F. for example,and air then passed therethrough at a slow enough rate to preventtemperature rise much above 250 F. When the oxidation reaction ceases topromote temperature increase, further air-blowing may or may not beresorted to, but if continued for the purpose of insuring sufficient orfurther oxidation the air-blowing may be extended for a suitable time,for example about one hour, at a higher temperature, for example atabout 300 F. In all cases, air-blowing should be carried out in a mannerto attain sufficient oxidation of the phosphorus in the phosphonatedoil, but should not be severe enough to oxidize more than minutequantities a of the unphosphorized oil molecules. Formation ofcarboxylic acids by oxidation of the oil hydrocarbons is to be avoidedas far as possible.

Saponiflcation.When suitable oxidation of the original phosphorizedmaterial has been accomplished to insure production of the desiredphosphonic acids, the charge is then mingled with a suitable metalhydroxide. such as calcium hydroxide, in the presence of dilutingquantities of water, and the batch heated at a temperature around orsomewhat above the boiling point of water for a time to effectsaponification or conversion of the phosphonic acids into the calciumsoap or salt, which material after filtering and washing is ready forincorporation into an appropriate mineral lubriacting oil such as thehigh viscosity index or low viscosity index oils herein described, whichoil in any given instance may or may not be of the same type as thatwhich is phosphorized.

Examples of phosphonates.-One specific method for the preparation ofcalcium phosphonates as herein described was as follows:

A paratfinic oil which was a highly solvent-refined lubricating oil ofSAE grade having 89 V. I.,

was heated to 300 F. and four separate five per cent additions (20%total) by weight of yellow phosphorus were made while heating from 300F. to 400 F. Heating was then continued until the temperature reachedthe boiling point of the oil (600 F. to 650 F.) and the temperature ofthe oil was held at that point for one-half to one hour. The oil washeated at all times in a nitrogen atmosphere. The oil was then cooled to200 F. and a stream of air was passed through the oil at a rate slowenough to prevent temperature rise above 250 F. After air-blowing causedno further evolution of heat, the oil was cooled, washed free ofwater-soluble acids, and'the calcium soap was prepared by heating theresulting phosphonic acid with calcium hydroxide at 300 F. for one-halfhour. The batch was filtered at 300 F. for removal of solids. Thisresulted in about 4% soap in about 96% unmodified oil. The same methodwas used to produce a similar product from a Western naphtheniclubricating oil having a viscosity of 600 seconds Saybolt Universal atF.

Another method which was employed is as follows:

Nine quarts of said SAE 20 grade oil having a V. I. of 89, werechlorinated at F. to F. by bubbling a rapid stream of chlorine throughthe oil. The process was continued until 2.0% of chlorine had beenabsorbed as judged by the increase in weight of the charge. Thechlorinated oil was then heated and stirred with 2% of yellowphosphorus. The temperature was raised to 475 F. and held at that pointfor three hours. (In another instance the temperature was raised toabout 625 F. which insured removal from the product of the trace ofchlorine retained when a temperature of only 475 F. was used.) The totalcharge was cooled to 200 F. and a rapid stream of air passed through theoil until heat evolution ceased (approximately 15 minutes), thetemperature being held in the meantime to a degree below 210 F. by useof cooling water. The charge was then filtered through a filterprecoated with a fine diatomaceous earth. A small sample was then waterwashed, and the acid number found to be 8.05. The total charge was thenagain air-blown for one hour at 200 F. to 210 F. to insure completeoxidation of the phosphorus, after which the acid number of a small,water-washed sample was found to be 8.25. The whole charge was thenwashed with an equal volume of water, and the wash water drawn oil.

The charge then heated and stirred for one hour with 200 grams ofcalcium hydroxide and 300 ml. of water at 200 F. The water wasevaporated oil by final heating to 230 F. The charge was cooled, 200 ml.of ethyl alcohol was added to insure complete saponification, and theheating and stirring was continued for one hour until the temperaturereached 300 F. The total charge was then filtered as above.

The filtered oil tested as follows:

Soap number 8.4 mg. KOH/g. oil Per cent phosphorus 0.25% Sulfate ash1.36% Soap number, calculated from ash 11.4 mg. KO'H/g. oil

Soap number, calculated from phosphorus 9.0 mg. KOH/g. oil

This signifie about 10% soap in about 90% of unmodified oil.

This same process may be used to treat naphthenic base oils as abovedescribed to produce corresponding products. Also all these proceduresare appropriate for the treatment of the other hydrocarbons mentioned toyield similar useful products.

The amount of yellow phosphorus :has been varied from about 0.5% toabout 20%, but most desirable conditions apparently have been obtainedwhen using phosphorus concentrations between about 2% and 10% based uponthe original charge. Phosphonation has been efiected at temperatures ashigh as 900 F. with contact time as low as about two minutes. Practicalconditions appear to be to phosphonate in a range between about 500 F.to 700 F. at a gauge pressure ofabout 50 lb./sq. in. for at least twominutes and preferably about five minutes or somewhat more.

As to the nature of the phosphorus compounds foimed there is evidencethat phosphonic acids are produced having a molecular weight in thegeneral range of 400 to 500. Aparently traces of compounds of the typeare formed. These may be very desirable oxidation inhibitors but on theother hand they may be objectionable in the combustion chamber wherelead gasolines are used due to the tendencies to form P205 and therebyform objectionable lead phosphates. It is to be noted that most of theP205 formed in the phospho'rizing operation will have been blown out andrecovered in the oxidizing stage. The remainder is removed by filtrationas the insoluble salt after saponiflcation.

The calcium soaps produced apparently are of the form and Thus thegeneral soap structures as related to any appropriate metal or otherbase will possess one or more of the following forms:

where R is any hydrocarbon radical or derivative thereof, and M is ametal or organic base material having alkaline properties, a being aninteger or fraction according to the valence of the metal or organicbase.

Similarly, sulfur or selenium may be substituted for oxygen. Alsoarsenic may be substituted for phosphorus for many uses, suitableproccesses being employed to produce the acids and their soaps. Thus,the soaps or salts used are of the following types:

where R is any hydrocarbon radical or derivative thereof, V is arsenicor phosphorus, X is oxygen, sulfur or selenium, M is a metal or organicbase material having alkaline properties, and a represents a fraction oran integer according to the valence of M. The invention also extends tothese features.

\ blown as described for the phosphonated hydrocarbon. The soap willthen be prepared as previously described. Instead of blowing to form theacidic materials by oxidation, thio-acids or selenoacids may be made bymixing a calculated amount of sulfur or selenium with the phosphonatedor arsenated hydrocarbon and heating below temperatures at which thearsenic or selenium would replace hydrogen in the hydrocarbon molecule.Such a temperature would be for example about 300 F. or below but highenough for the reaction to proceed.

Final product As in the case of the thiophosphates previously described,the described phosphorus acid salts may be used as a third constituentalong with the phenol-thio-ether salts in addition to the sulfonates asthe detergent constituent.

In blending oils according to the present inven- I tion, it has beenpreviously indicated that it is necessary merely t add the salts ordescribed 011 concentrates to an appropriate base lubricating oil inproportion to yield the desired content of each of the indicated saltsor soaps. In other words, around 1% or a little more of the sulfonate isused, and around 1% or a little less of the other constituent orconstituents is used. Thus, for practical uses about 1.2% of thesulfonate is desirably employed in conJunction with around three-fourthsof one percent (0.75%) of the phenol-thio-ether salt or one of thephosphorus compounds, although perhaps around 0.4% or 0.5% of any of thephosphorus compounds or of the phenol-thio-ether salt is adequate. Theover-all ranges probably run around 0.2% or 0.3% to 2% or 3% of each ofthe additives employed. The described additives are all amplydispersible in lubricating oils of high viscosity index, i. e. highlyparaflinic characteristics, and adequately adapt such oils to uses ininternal combustion engines of the severe service type. Also theseadditives are equally usable in lower V. I. oils, e. g. naphthenic oilsand oils of mixed base type. With respect to the percenta ranges of thevarious compounds, other than as just stated, other ranges indicatedelsewhere herein also may be employed where advantageous.

Metals.-Regarding the metal constituents of the oil-soluble salts usableas the various types of additives described for the Various finalproducts herein disclosed, it appears that a wider range of metals maybe employed in the phosphorus-containing additives than in thesulfonates or in the described phenolics.

Thus, it appears that iron, lead and copper sulfonates are especiallyobjectionable both because their sulfonates act as catalysts foroxidation or the production of corrosive conditions and because theother described types of salts of these metals tend to produce similareffects. On the other hand, where other metals sometimes appear toofl'er some objection in sulfonates, e. g. thioether salts described.These phenomena are employed in the various organicphosphorus-containing compounds described, and in conjunction withacceptable sulfonates such as calcium sulfonate, these other metals inthe phosphorustionable.

containing compounds are not necessarily objec- Again, it appears thatthose metals which are objectionable in sulfonates, are likewiseobjectionable if they appear in the phenol thioether salts described.These phenomena are possibly explainable by the theory that the metalconstituent is sufficiently tightly held to the acidic group of thephosphorus compound so that the stronger acid constituent of thesulfonate has no effect toward releasing the metal of the phosphoruscompound. On the other hand, in view of the fact that the sulfonicconstituent represents much stronger acids than are represented by thephenol thioether compounds, if one of the objectionable metals ispresent in the phenol thioether salt, it is possibly partly releasedtherefrom and an exchange of metals between the sulfonates and thephenolics results, thereby producing objectionable metal sulfonate. Ingeneral, it may be said that most metals except iron, lead and copper,which will produce oil-soluble forms of the phosphorus compoundsdescribed, may be used in said phosphorus compounds. also appears that,in producing the phenolic salts described, those metals should be usedwhose sulfonates are not objectionable. Also, the oil base stock is afactor in the oxidaion, and the salt of a metal which is catalytic inone oil is not necessarily sufficiently catalytic in another oil to beobjectionable. Generally speaking, the more parafiinic oils requiregreater care in selection of metals for the additive salts. Thisapplies, for example, to oils in the 80 V. I. to 100 V. 1. range.

It may be stated that for all purposes the .calcium salts of all of thevarious additives mentioned are acceptable and probably preferable.There is good evidence that the barium and strontium salts are likewiseacceptable. For the most part, salts of the other alkaline earth metal,magnesium seem to be acceptable. Again zinc salts seem to be good forall of the additives, and appear to be very desirable for thephosphorus-containing compounds described.

Thus, the invention lies in oils containing oilsoluble sulfonates andone or more of the other types of constituents described, wherein theoils are free from salts and other constituents, which would act in thecomposition to impart or to induce corrosive conditions. In a morespecific aspect the invention lies in lubricating oils containing minorproportions of calcium salts of sulfonic acids, and calcium salts of oneor more of the other constituents; that is, a calcium salt of one of thephosphorus-containing compounds and/or a calcium salt of the phenolicthioethers described, the oils being free from any added constituentwhich would promote corrosive conditions during use. In a somewhatbroader aspect, the invention lies in the use of oil-soluble sulfonateswith phenolic thioether salts of metals whose sulfonates are free fromthe characteristic of producing corrosive conditions, with or withoutsimilar metal salts of the phosphorus com 'pound described. Theinvention also resides in the use in lubricating oils of oil-solublesulfonates of metals whose sulfonates do not promote corrcsiveconditions in use, with any of the phosphorus-containing compoundsdescribed containing any metal which renders the salt soluble,

other than iron, lead or copper, or more particularly containing onlymetals whose sulfonates are not objectionable.

More specifically, alkaline earth metal sulfonates and phenolics areused with alkaline earth metals or zinc salts of the phosphorus commandsdescribed, or with the described phosphorous salts of any of the metalswhose sulfonates are not objectionable. This includes, in addition tothe calcium, strontium and barium salts, the zinc salts and probably themagnesium salts of the phenolics as well as of the sulfonates and of thephosphorus-containing compounds. Again, where conditions are not sosevere as in the case of Diesel engines and high out-put aviationengines, it may be possible to use phenolic thioether salts of metalswhose sulfonates are objectionable. This appears to be' true especiallywhere one of the mentioned types of phosphorus compounds is employed asa third additive. For instance, it has been found that where very smallamounts of objectionable sulfonates (such as iron sulfonates) appear incalcium sulfonates used in the presence of the mentioned types ofphosphorus-containing salts, the objectionable characteristics of theiron sulfonate or other objectionable sulfonate have been sufficientlyovercome for use in lubricating Diesel engines.

Thus, this invention resides also in the employment, along withacceptable sulfonates and acceptable phenolics as described, of salts ofthe described types of phosphorus compounds as a third constituent. And,the invention also resides in lubricating oils containing describedacceptable oil-soluble sulfonates with described oil-soluble metalphenolics and/or described oil-soluble metal-containing phosphoruscompounds, where the oils are free from salts of metals which wouldproduce corrosive conditions in the oils when in use in any givenengine.

These combinations of described additives have produced lubricating oilsof high V. I. type which have stood up under severe service conditionsfar better than any other combinations of additives. Resin and varnishformation and consequent ring sticking have been well controlled, andcorrosion has been so well overcome that acid numbers in severe 500 hourtests have not exceeded about 0.5.

Various modifications of this invention and within the scope of theappended claims will occur to the skilled lubricating chemist.

I claim:

1. A lubricating oil comprising mineral lubrieating oil and a, minorproportion in the order of from about 0.5% to about 3% of oil-solublemixed green acid soaps and mahogany acid soaps obtained from thesulfonation of a mineral lubricating oil followed by neutralization andformation of the oil-soluble sulfonates and separation of all solids thecomposition containing appreciable amounts of green acid soaps which aresolubilized by the mahogany acid soaps present.

2. An oil according to claim 1 containing a minor proportion of ananti-corrosion agent of the class consisting of oil-soluble metal salts.of alkylated phenol-thio-ethers, oil-soluble metal thio-phosphates ofaliphatic alcohols, and oilsoluble metal salts of phosphonic acidsproduced by phosphorizing mineral oil fractions and air blowing saidphosphonated fractions.

3. A lubricating oil for severe service combustion engines comprisingmineral lubricating oil, and minor proportions within the range of about0.2% to about 3% of each of oil-soluble mineral oil sulfonates free fromcorrosion inducing salts, and an anti-corrosion agent of the classconsisting of oil-soluble metal salts of alkylated phenolthio-ethers,oil-soluble metal thiophosphates from aliphatic alcohols, andoil-soluble metal salts of phosphonic acids produced from mineral oilfractions the sulionates being mixed green acid soaps and mahogany acidsoaps, the composition containing appreciable amounts of green acidsoaps which are solubilized by the mahogany acid soaps present.

4. An oil according to claim 3 wherein the sulionates are calciumsulionates.

5. An oil according to claim 3 wherein the 8111- fonates are mixed greenacid and mahogany acid sulionates obtained by sulionating a mineral oiltraction and neutralizing the mixed sulfonic acids in situ and obtainingin situ the desired oil-soluble mixed sulfonates. and separating thesolids.

6. A lubricating oil comprising mineral lubricating oil and a minorproportion of oil soluble mixed green acid soaps and mahogany acidsoaps, the composition containing appreciable amounts of green acidsoaps which are solubilized by the mahogany acid soaps present.

7. An oil according to claim 1 wherein the suli'onates are calciumsulionates.

8. An oil according to claim 6 wherein the sulfonates are calciumsulfonates.

9. A lubricating oil comprising mineral lubricating oil and a minorproportion of oil soluble mixed green acid soaps and mahogany acidsoaps, free from corrosion inducing salts, the composition containingappreciable amounts of green acid soaps which are solubilized by themahogany acid soaps present.

10. An oil according to claim 6 also containing a minor proportion of ananti-corrosion agent.

11. An oil according to claim 6 substantially free from corrosioninducing salts and also containing a minor proportion of ananti-corrosion agentwhich is an oil-soluble metal salt or an alkylatedphenol thio-ether.

12. An oil according to claim 6 free from corrosion producingconstituents and also containing a minor proportion of an anti-corrosionagent which is an oil-soluble thiophosphate.

13. An oil according to claim 6 which is substantially tree ofcorrosition producing salts and which also contains a minor proportionof an anti-corrosion agent which is an oil-soluble compound produced byphosphorizing a mineral oil fraction and air blowing the phosphorizedmaterial to yield phosphonic acids.

14. An 011 according to claim 6 which is substantially free of corrosionproducing salts and which also contains a minor proportion of ananti-corrosion agent which is an oil-soluble metal salt produced by thereaction of phosphorus pentasulflde with an aliphatic alcohol.

15. An oil according to claim 6 which is substantially free of corrosionproducing salts and which also contains a minor proportion of ananti-corrosion agent which is an oil-soluble salt or the reactionproduct of phosphorus pentasulfide with octyl alcohol.

16. An oil according to claim 6 which is substantially free ofcorrosition producing salts and which also contains a minor proportionoi. an anti-corrosition agent which is an' oil-soluble metal salt of thereaction product of methyl cyclohexanol with phosphorus pentasulflde.

1'7. An oil according to claim 6 which is substantially tree ofcorrosion producing salts and which also contains a minor proportion ofan anti-corrosion agent which is a metal salt of the reaction product ofan aliphatic alcohol with phosphorus pentasulflde.

18. An oil according to claim 6 which is substantially free of corrosionproducing salts and which contains a minor proportion of ananticorrosion agent of the class consisting of oilsoluble metal salts ofalkylated phenol-thicethers, oil-soluble metal thiophosphates 0taliphatic alcohols, and oil-soluble metal salts of phosphonic acidsproduced by phosphorizing mineral oil fractions and air blowing saidphosphonated fractions.

19. An oil according to class 6 which is substantially tree fromcorrosition producing salts and which also contains minor proportions ofan anti-corrosion agent of the class consisting of oilsoluble metalsalts of alkylated phenol-thicethers, oil-soluble metal thiophosphatesfrom allphatic alcohols, and oil-soluble metal salts of phosphonic acidsproduced from mineral oil fractions.

20. An oil according to claim 6 which is substantially free of corrosionproducing salts and which also contains a minor proportion of ananticorrosion agent comprising both an oil-soluble metal salt of analkylated polyphenol sulfide and an oil-soluble metal salt oi an organicphosphorus-containing acid.

EARL AMO'I'I'.

CERTIFICATE OF CORRECTION.

Patent No. 2, 78,820. June 19, 191

EARL AMOTI.

It is hereby certifi ed that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page. 2,first column, line 11, for "issigned" read assigned-; line 68, for "150c." read "1509 F.--; and second column, line 59, for "acceptacle" read"acceptable---; page )4, first column, line 66, after "sulfur" strikeout the comma and insert instead a period; and second column, line 11.2,for "powder" read -power--; page 7, first column, line LU}, for"lubriacting" read -1ubricating-; page 8, first column, line 1, for"Aparently" read --Apparently--; and second column, line 71, strike outthioether salts described. These phenomena" and insert instead -tin oraluminum, where these other metals--'; page 10, second column, lines 12,M and 514., for "corrosition" read --COIIO? sion--; same page andcolumn, line 55, for "class" read -claim--; and that the said LettersPatent should be read with this correction therein that the same mayconform to the record of the case in the Patent Office.

Signed and sealed this 2 rd day of October, A. D. 191

Leslie Frazer (Seal) First Assistant Commissioner of Patents.

CERTIFICATE OF CORRECTION.

Patent No. 2, 7 20. June 19, 191

EARL mom.

It is herebi' certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page. 2,first column, line 11, for issigned read --assigned-; line 68, for -1500." read "1509 F.--; and second column, line 59, for "acoeptacle" read--acceptable--; page 1.1., first column, line 66, after "sulfur" strikeout the comma and insert instead a period; and second colunin, line11.2, for "powder" --power--;

read page 7, first column, line 1 5, for "lubriacting" read-lubricating--; page 8, first column, line 1, for "Aparently" read--Apparently--;

and second column, line "(1 strike out "thioether salts described. Thesephenomena" and insert instead -tin or aluminum, where these 0 thermetals-"g page 10, second column, lines 12, 11; and 51;, for"corrosition" read -OOI"I'O sion--' same page and column, line 55, for"class" read --claim--; and that the said Letters Patent should be readwith this correction therein that the same may conform in the record ofthe case in the Patent Office.

Signed and sealed this 25rd day of October, A. D. 1915.

Leslie Frazer (Seal) First Assistant Commissioner of Patents.

